Getting a Subset of Records along with Total Record Count

Question

I\'m working on returning a recordset from SQL Server 2008 to do some pagination. I\'m only returning 15 records at a time, but I need to have the total number of matches along

Answer 1

I've handled a situation a bit similar to this in the past by not bothering to determine a definite row count, but using the query plan to give me an estimated row count, a bit like the first item in this link describes:

http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=108658

The intention was then to deliver whatever rows have been asked for within the range (from say 900-915) and then returning the estimated row count, like

rows 900-915 of approx. 990

which avoided having to count all rows. Once the user moves beyond that point, I just showed

rows 1000-1015 of approx. 1015

i.e. just taking the last requested row as my new estimate.

Answer 2

Here is what I have done (and its just as fast, no matter which records I return):

--Parameters include:
@pageNum int = 1,
@pageSize int = 0,



DECLARE 
    @pageStart int,
    @pageEnd int

SELECT
    @pageStart = @pageSize * @pageNum - (@pageSize - 1),
    @pageEnd = @pageSize * @pageNum;


SET NOCOUNT ON;
WITH tempTable AS (
    SELECT
        ROW_NUMBER() OVER (ORDER BY FirstName ASC) AS RowNumber,
        FirstName
        , LastName
    FROM People
    WHERE Active = 1
)

SELECT
    (SELECT COUNT(*) FROM tempTable) AS TotalRows,
    *
FROM tempTable
WHERE @pageEnd = 0
OR RowNumber BETWEEN @pageStart AND @pageEnd
ORDER BY RowNumber